I need to get informations out from my tree of Thunderbird message folders (which contains a large amount of email).
I need to be able to search the messages (optionally the attachments) and to report to the calling program.
There is some python module able to do it?
As you apparently figured out yourself already, yes.
The vanilla python module mailbox
, which exists in any python 2 or 3 version, is all you need: